California Code, Vehicle Code - VEH § 24007.2

If a dealer, or a person holding a retail seller's permit, sells to an elderly low-income person, as defined in Section 39026.5 of the Health and Safety Code, a 1966 through 1970 model year motor vehicle which is not equipped, as required pursuant to Sections 43654 and 43656 of that code, with a certified device to control its exhaust emission of oxides of nitrogen, the dealer or such person, as the case may be, shall install the required certified device on the motor vehicle without cost to the elderly low-income person.